Take your Hammerhead to Manhattan and destroy the two Police depots there. After that the criminals will stop shooting and many will love you dearly. I did this in a Starflier so it should be not be overly difficult in a Hammerhead.
The Bounty Hunters also have depots (Deshima) and
every outlaw hates them. Just in case you run out of police depots before you have rebalanced your rep sheet enough.
For survival training, buy a Starflier with a class 2 graviton shield and whatever guns you like, and take it to the Silverton Flying School^W^WAsteroid Field in Colorado. Start going back and forth between the New York jump hole and Pueblo Station, and tangle with Xenos until you have become good enough so that the number of shield batteries does not decrease over time. You may use batts but you have to loot them back and on average the number of batts should go up (or at the very least remain the same). This will teach you dodging enemy gun fire.
Then buy a Drake and go to the Omegas/Omicrons (except Alpha/Gamma where the enemies are level 18/19) and learn dodging enemy gun fire plus missiles plus mines. Make sure that at least the dominant criminal faction (i.e. Outcasts/Corsairs) or the Bounty Hunters are hostile, though, because otherwise there would be no point. All the other factions are complete pushovers, except for the GMG.
Then buy a Banshee and head into Omicron Alpha/Gamma, whichever happens to be hostile at that point. This will teach you do serious damage while dodging high-powered mines/missiles/gunfire (level 18/19 NPC ships tend to have almost double the normal armour).
After that you should be able to survive indefinitely in any hostile environment in the Sirius sector - but you'll probably have a hard time downgrading from a light fighter to a flying brick like the Hammerhead or Sabre (not to mention the mobile weapons platform known as Titan).